The Data Encryption Standard (DES)

Q1: What are substitution ciphers? How do they differ from one-time pads? Which is better for the IS manager to employ? Explain your answer.

Q2: What is the Data Encryption Standard (DES)? What is triple DES? How did the Rijndael protocol enhance DES?

Q3: What is an intrusion detection system (IDS)? What are the two types of IDS? Provide examples of at least three things that a properly configured IDS does for the IS manager.

Q4: Is intrusion prevention a proactive or reactive approach? Why? Provide an example. What is a digital signature? How does digital signature enhance the authenticity and integrity of data? Provide at least two examples.

Solution Preview

Q1: What are substitution ciphers? How do they differ from one-time pads? Which is better for the IS manager to employ? Explain your answer.
Substitution ciphers are a code that replaces every letter with a symbol, drawing, number, color, picture or another letter type. This means that if the first letter, D, is replaced as the color blue then every D will be blue. A one time pad is a cipher that is almost un-breakable. A one time cipher can only be cracked by an encryption key from a random source. Since one time pads are virtually un-crack able, they would be the most secure for an IS manager to use.
Q2: What is the Data Encryption Standard (DES)? What is triple DES? How did the Rijndael protocol enhance DES?
The Data Encryption Standard (DES) was developed in the 1970's. Using a private key algorithm and vulnerable to attacks using brute force due to its small size, DES was designed to encrypt data. Because the DES encryption was so easy to break, today anyone who needs high security uses a triple DES. 56 bit keys are ...

Solution Summary

The Data Encryption Standard (DES) is fully exhibited. References are also listed to promote research.